Youth is marked at its commencement by the changes which occur
at puberty—the development of the genitals in both sexes, the
appearance of hair on the genitals, the appearance of a beard in
the male, the development of the breasts in the female, the
appearance of the monthly flow in the female, and the ability
to secrete semen in the male. Marked mental changes now occur,
and the generative functions are perfected. Youth terminates at
the age of legal majority, twenty-one years, or perhaps the period
ought to be extended to twenty-five years of age, as it is with some
nations.
Manhood (or Womanhood) is the period of perfection of all the bodily and mental powers. It ceases in woman with the cessation of the monthly flow at about forty-five years of age; but in man it often extends to a much later period of life.
Old Age begins with the decay of the bodily and mental faculties, and is characterized by wrinkling of the skin, loss of the teeth, whitening of the hair, and feebleness of the limbs. In its later stages decay of the mental faculties, deafness, obscurity or loss of vision, and bowing of the spine are added.
2. Duration of Human Life.—The chances of human life form an important subject of inquiry, and on deductions from comparisons of birth and death rates is founded the system of annuities, insurance against loss in sickness, and the insurance of lives. Since the establishment of compulsory registration of deaths, our knowledge of the ordinary and extraordinary chances of human life has been extended, and surer data are available for calculations of probabilities of life, of survivorships, and of the payments which ought to be made in benefit clubs (see Insurance).
3. Personal Identity.—Where the identity has to be established or disproved after long absence, exposure to foreign climates and hardships, wounds, &c., the problem has often been extremely difficult. The data for identifying a person are individual and family likeness, stature, the colour of the eyes, peculiarities of garb and manner, recollection of antecedent events, but more especially marks on the persons either congenital or acquired. Such are naevi or mother's marks, scars, and disunited or badly united fractures, known to have existed upon the missing person (see Identification). In the case of the living, identification is more often a matter for the police officer than for the medical man. Bertillon and Galton have each devised methods for the identification of criminals (see Anthropometry, and Fingerprints).
4. Marriage.—Under this head the medical jurist has to deal principally with the nubile age, viewed in the light of nature and according to legislative enactments, and with such physical circumstances as affect the legality of marriages, or justify divorce.
In Great Britain the age at which the sexes are first capable of propagating the species is later than in more southern climes. Ordinarily it does not occur before fifteen years of age for the male and fourteen for the female; exceptionally it occurs at the ages of thirteen and of twelve (or even less) respectively in the male and female. By law, nevertheless, parents and guardians may, in England at all events, forbid the marriage of young people till the age of legal majority. The only physical circumstances which in Great Britain form a bar to marriage are physical inability to consummate, and the insanity of one of the parties at the time of marriage. Both those circumstances have been pleaded and sustained in the law courts. In other countries minor physical circumstances, as disease, are held to invalidate marriage.
5. Impotence and Sterility.—These are of importance in connexion with legitimacy, divorce and criminal assaults. Impotence and sterility may arise from organic or from functional causes, and may be curable or incurable. Impotence (q.v.) is taken cognisance of by the law courts as a ground of divorce, and might, of course, be urged as a defence in a case of rape. Sterility is not a ground of divorce, but might be a question of importance in cases of legitimacy.
6. Pregnancy.—This subject presents one of the widest fields for medico-legal evidence. The limits of age between which it is possible, the limits of utero-gestation, and the signs of pregnancy may all in turn be the subjects of investigation.
The limits of age between which pregnancy is possible are usually fixed by the appearance and cessation of the monthly flow; and these ordinarily begin about fourteen and cease at forty-five years of age. Exceptionally they appear as early as the tenth year, and may not cease till the end of the fifth decade of life. Cases, however, have occurred where a woman has conceived before menstruating; and a few doubtful cases of conception are recorded in women upwards of fifty or even sixty years of age. The general fact of pregnancy being limited by the age of puberty on the one hand and the cessation of the monthly flow—or fifty-three or fifty-four years as the extreme limit of age—must be accepted as the safest guide in practice.
The limits of utero-gestation are not in England fixed by legislation. The French code fixes the extreme limit of three hundred days. The ordinary period is forty weeks and a half, or two hundred and eighty-three days from the cessation of the last monthly flux. The limit of three hundred days, as fixed by the French code, is perhaps never exceeded, if ever reached. The uncertainty of females in fixing the exact date of conception has given rise to the discrepant opinions of physiologists on the subject. It is well known, however, that among the higher animals the period is not precise; and impregnation and conception need not necessarily be coincident.
The signs of pregnancy are of the utmost importance to the medical jurist. He may be called upon to pronounce upon the virtue of a female, to sustain or rebut a plea for divorce, to determine whether a capital sentence shall be carried out, or to determine whether it is probable that an heir will be born to an estate. Medical jurists classify the signs of pregnancy as uncertain or certain; it is the former which are most regarded by the public, but the latter are alone of probative value to the jurist. The usual and uncertain signs are the cessation of the monthly flow, nausea, sickness, a darkening of the areola and the formation of a secondary areola around the nipple, enlargement of the breasts, increased size of the abdomen, the formation of a tumour in the womb, quickening, and the motions of the foetus. Also uncertain are the uterine souffle, which is a peculiar soft sound heard over the abdomen and synchronous with the maternal pulse and ballottement or the examination for a floating tumour in the abdomen between the fifth and eighth months of pregnancy. The certain signs of pregnancy are the foetal limbs palpated through the abdomen by the physician, the pulsations of the foetal heart heard by means of the stethoscope, the pulsations being much quicker and not synchronous with the maternal pulse. This latter is inapplicable before the fourth month of gestation.
7. Parturition.—The imminence of the process of parturition is of comparatively little interest to the medical jurist; but the signs of recent delivery are all-important. These signs are the bruised, swollen, and lacerated state of the external genitals, relaxation and dilatation of the vagina and womb, the existence of a peculiar vaginal discharge known as the lochia, a relaxed and fissured condition of the abdominal walls, a peculiar aspect of the countenance, and the distended state of the breasts due to the secretion of milk. The lochial discharge is the most characteristic sign. All the signs may disappear within ten days of delivery, though this is not usual.
Connected with parturition, the question of viability (potentiality for life) of the child is not unimportant. After the intra-uterine age of seven months is reached a child is certainly viable. The period at which the foetus becomes viable cannot be stated with certainty; but five calendar months, or one hundred and fifty days, is perhaps the nearest approximation. The viability of a child is judged by its size and weight, its general state of development; the state of the skin, hair, and nails; its strength or feebleness, the ability to cry, and its power of taking maternal nourishment. The question of viability has important bearings upon the crime of infanticide. In the case of succession to property the meaning of “born alive” is different from the meaning of the same expression as used respecting infanticide. In questions of tenancy by the curtesy (q.v.) it has been decided that any kind of motion of the child, as a twitching and tremulous motion of the lips, is sufficient evidence of live-birth. By the French code, however, no child that is born alive can inherit, unless it is born viable. As regards infanticide, proof of a conclusive separate existence of the child is demanded before live-birth is admitted.
The subject of superfoetation and superfecundation, or the possibility of two conceptions having occurred resulting in the birth of twins with a considerable intervening interval, is obscure and has given rise to much controversy. There is much, however (e.g. the existence of a double or bifid uterus), to countenance the view that a double conception is possible.
8. Monsters and Hermaphrodites.—To destroy any living human birth, however unlike a human creature it may be, is to commit a crime. Blackstone states that a monster which hath not the shape of mankind hath no inheritable blood; but the law has not defined a monster, nor what constitutes a human form. The same author states that if, in spite of deformity, the product of birth has human shape, it may be an heir. Hermaphrodites are beings with malformations of the sexual organs, simulating a double sex. Physiologists do not admit, however, the existence of true hermaphrodites with double perfect organs, capable of performing the functions of both sexes.
